For the past decade, Japan has been expanding the use of woody biomass for power generation to replace or be mixed and burned with coal. The country is now the second-largest wood pellet consumer in the world after the U.K. But there are concerns that burning wood pellets or palm kernel shells to generate electricity might not be safe. In the past few years, there have been at least 14 fires, explosions and accidents at biomass power plants across Japan. These incidents, combined with rising prices, pollution concerns and growing opposition are leading some to question the future of Japan’s large-scale biomass plants, an estimated 34 of which produce 3.5 gigawatts of power. …in the rush to expand plants, corners may have been cut, including improper construction and substandard storage and processing of wood pellets, says Roger Smith, Japan director at nonprofit Mighty Earth.